<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Theme</title>
  </head>
  <body>
    <div id="app"></div>
    <script>
      document.body.style.background = `url(https://source.unsplash.com/random/${window.innerWidth}x${window.innerHeight}?city,night) no-repeat`
    </script>
  </body>
</html>
